Unison

TL;DR: Do not ask questions or ask for help in issues. Upgrade to the latest release. Please also read before interacting with the issue tracker or asking for help. Unison has been in use for over 25 years and many people use it to synchronize data they care about. Unison works across platforms, allowing you to synchronize a Windows laptop with a Unix server, for example. Unlike simple mirroring or backup utilities, Unison can deal with updates to both replicas of a distributed directory structure. Updates that do not conflict can be propagated automatically. Conflicting updates are detected and displayed. Unlike many network filesystems, Unison copies data so that already-synchronized data can be read and written while offline. Unison works between any pair of machines connected to the internet, typically communicating over ssh, but also directly over TCP. It is careful with network bandwidth, and runs well over slow links. Transfers of small updates to large files are optimized using a compression protocol similar to rsync. Unison can run in "repeat" mode with a filesystem monitor, so that changes are synchronized soon after they happen. Unison is Free; full source code is available under the GNU Public License, Version 3. Unison activity is now centered on the two Unison mailinglists for discussion and Unison's github page for code, issues and a wiki. The unison-users@ list is appropriate for asking for help. The unison-hackers@ list is appropriate for discussions where participants might be reading source code in order to inform the discussion. The Unison project provides Unison as source code. Many packaging systems (including GNU/Linux distributions) provide binary packages of Unison. Results from Continuous Integration builds, while performed for the purposes of testing, are available for use on a limited set of platforms. See the top-level wiki page for a variety of information, including how to access Unison documentation. You should use the most recent formal release, or a newer version from git. Earlier versions are no longer maintained, and bug reports are not accepted about these versions. This is true even though many packaging systems (including GNU/Linux distributions) continue to have 2.51 or even 2.48. The master branch in git historically has been quite stable.